A Meta-Analysis of Response Strategies and Interfering Factors of Kin Recognition in Plants

Conspecific plants exhibit morphological and biochemical plasticity in response to genetic relatedness in varying environments. However, the response strategies and factors influencing kin recognition in plants remain unclear. Meta-analysis is an approach to synthesize the effect size of plant–plant and plant–environment interactions. Here, we present the first case of a meta-analysis for response strategies and interfering factors in relatedness-mediated plant–plant interactions. We synthesized the effect of kin recognition on plant performance and environmental factors, based on 104 studies with 4045 cases. As a result, we found that kin recognition reduces root biomass, root length, root–shoot ratio, and lateral root number, lowering belowground competition. Furthermore, kin cooperation enhances aboveground light acquisition by increasing leaf area and boosts reproductive success by increasing seed biomass. The kinship effects are significantly influenced by both biotic (e.g., root interactions, kinship coefficient r, sex systems, recognition level) and abiotic factors (e.g., nutrient levels, experiment types, stress type, planting spacing and duration). Our meta-analysis highlights the response strategies and interfering factors of kin recognition in plant performance and environment dynamics, laying the foundation for further research on its ecological evolution and agricultural applications.